Abductor pollicis brevis rerouting and first web deepening for clasped thumb deformity in arthrogryposis multiplex congenita

Abstract

In this study, we retrospectively reviewed our results of managing the clasped thumb deformity in arthrogryposis multiplex congenita patients with first web space deepening and abductor pollicis brevis (APB) rerouting. Twenty-six thumb deformities in 16 children with a mean age of 6.2 years were treated with a mean follow-up of 89.6 months. Following reconstruction with the Spinner flap, the mean angle of the first and second metacarpal axis (M1M2) showed significant improvement from 42° to 61° indicating a wider first web space, and the postoperative mean angle of the thumb proximal phalanx to its metacarpal axis (M1P1) was reduced from 41° to 18°, indicative of a straighter thumb. Following reconstruction with a double-opposing Z-plasty, the mean M1M2 and M1P1 also improved from 38° to 52° and 18° to 9°, respectively. Rerouting of the APB with first web deepening is an efficient and reproducible procedure in improving thumb position. Level of evidence III